Background: Post-thoracotomy pain syndrome affects many lung cancer patients and survivors. In some patients, the symptom is long-lasting and refractory despite currently available treatment, having a significant impact on their quality of life. Acupuncture can be an effective complementary modality in the management of certain types of pain. Both post-operative pain and neuropathic pain in cancer patients have been shown to respond to acupuncture treatment. We have conducted a pilot study testing the feasibility of planting small intradermal acupuncture needles perioperatively to reduce post-thoracotomy pain. We found the intervention feasible in the current clinical practice setting and well received by patients and surgeons. [unreadable] Objectives: We propose to conduct a randomized controlled study to further evaluate the effectiveness of such acupuncture technique for post-thoracotomy pain syndrome. The specific aims are to 1) determine whether acupuncture using intradermal acupuncture needles reduces chronic post-thoracotomy pain compared to placebo; 2) determine whether acupuncture using intradermal acupuncture needles reduces acute post-thoracotomy pain compared to placebo. [unreadable] Methods: A prospective, randomized placebo-controlled intervention study of acupuncture in 140 cancer patients undergoing thoracotomy. Small intradermal acupuncture needles or placebo needles will be placed mainly along the spine prior to surgery. The needles stay in place for a total of four weeks. Numerical rating scale of pain, Brief Pain Inventory (BPI), use of opioids and non-opioids analgesics will be evaluated at baseline and postoperatively. The primary comparison is BPI scores at Day 30 between the true acupuncture group and the placebo acupuncture group. [unreadable] Significance: Post-thoracotomy pain syndrome is a difficult-to-treat sequela of surgical treatment of lung cancer. The proposed study will test the effectiveness of acupuncture, a complementary modality, in treating this symptom. If results are promising, we would propose a large, multi-institutional randomized trial. The research has the potential of leading to a new treatment option to improve the quality of life of cancer patients and cancer survivors. [unreadable] [unreadable] [unreadable]